Bushing



E. E. TOMPKINS.

BUSHING.

APPLICATION FILED MAR. 31. 1919.

1,373,778, Patented Apr. 5, 1921.

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' rusnnfxieg j To allwhom it mayconcern .1

Be-it lmown that I, ERNEST ESTO PKINS, a citizen of the United States, residing at Philadelphia, in the county of'Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Bushings, of which the following is' a specification. I, g

The object of this invention is to provide an improved bushing, particularly for removably connecting together metal and yielding objects, such as those made of rubber.

In the manufacture and use of injectors of various sorts, such for instance as hypodermic-needles, rectal and pelvic syringes and the like, it has long been found necessary to employ a piston-like plunger of rubber closely fitting against the inside walls of the syringe, and operatingsaid plunger to eject the fluid contents by connecting to each of them a rod of suflicient length to extend beyond the limits of the syringetube, when the plunger is in its innermost position.

However, it frequently occurs that the union or connection between the plunger and the operating-rod does not hold, upon manually shifting the latter, and that as a result they become separated, thus destroying the usefulness of the articles of which they form a part, as these two members can not be satisfactorily reconnected. Furthermore, through lack of use, a plunger often sticks to the sides of the containing-tube, and the operating-rod breaks from the plunger in trying to: twist the latter free from engagement with said tube.

As a result of these difficulties which have long been encountered in the use of such articles, the present objectis to provide an internally threaded metallic bushing, provided with means extending well into the body of a plunger of rubber or other yield.- ing material. and after screwing the usual operating rod into said bushing said projectors operate to prevent the separation of said bushing from said plunger.

With these and other objects in view, the

invention comprises certain novel details of construction and operation as hereinafter fully brought out in the following description, when read in conjunction with the accompanying drawings, in which Figure 1 is a longitudinal diametrical section of a syr- V Specification of lhettersratentr -jfi raana'aasr; 5.1.3211.

Applicationfiled'lllarch 31,1919. 'seriai nq. 286,990; 1

inge plunger provided with one form of the improved'bushing; and Fig. 2 is aside elevation ofthe 'bush'ing ofv Fig. 1, per 86."

Referring to the drawings, a common "type of plunger isshown as comprising a 'solidj member 1, with a rounded fluid-ejecting frontal'surface 2,and'-provided peripherally intermediate of its ends with a groove 3', in -which,may be placed 1 a suitable packing or the like, or otherwise left empty.

A bushing, comprising a cylindrical internally threaded section 4, is molded axially into the end portion of said plunger.

opposite to the frontal surface 2, and is provided at its free end portion with an outwardly directed eripheral'flange, 5, while its innermost end portion is split or cut to provide spaced ears or projecting lugs 6,

adapted to be reversely bent into positions at acute. angles with the adjacent sides of the cvlindricalportion 4 of the bushing, in

which position, with the material of the plunger surrounding them, any pull outwardly upon an operating rod screwedinto said bushing only tends to increase the hold of the bushmg. upon the surrounding plunger material, asportions ofthe latterbecome wedged more tightly between the bushing cylinder and the diverging lugs or ears.

Finally, the bushing as illustrated by Fig. 2 is provided with outwardly bent lugs or ears, which it"wil'l be. noted are preferably. directed sharply rearwardly'and having their lowermost end portions 7 flexed,

so that one of the longitudinal edges of eachof said cars is of greater and constantly increasing distance from the adjacent side of the cylinder 4 than-the other of said edges.

Furthermore, this type of bushing,-1n adgitudinally from the rubber plunger, .is of such shape that, if the plunger sticks to the sides of the containing-tube, and a righthand. twist is'given to the operating rod condition to preventing itsbeing removed lonnected thereto, the ears 7 operate towedge between themselves and the adjacent 'por-' tions of the cylinder the interposed material of saidplunger.

Thus it is obvious; that in constructing these various modifications of the general improved bushing, the primary object has been to prevent the said bushing from'being removed from a surrounding plunger as the result; of any relativamovement whatsoeyer that might be giyen to the connected elements. And, while a plunger for 7 articles used by physicians and surgeons has been described, it isto be understood thatthis invention is equally adaptable to the bushings in connecting the usual metal'rods to the rubberball plungers of lavatorytanks, and in fact to any additional articles made of rubber or similar yielding material, to which it is desirable to connect other elements.

- Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States is 1. A bushing comprising an internally threaded cylinder, and longitudinally extending fingers arranged outwardly of and near the cylinder in a surrounding group,

'said fingersbeing secured to the cylinder and twisted upon their longitudinal axes for forming spirals.

2. A bushing comprising an internally threaded cylinder, and'iiiigers secured to the forward end thereof and bent outwardly and rearwardly to extend longitudinally of the cylinder, said fingers being twisted upon theirlongitudinal axes.

7 v 3. A bushing comprising a cylinder, fin

an outwardly extending flange formed upon 6 the rear end of the cylinder..

In testimony whereof I have afiixedmy signature. a ERNEST'E. TOMPKINS. 

